An electronic controller is well known in the industry for collecting and processing data relevant, and often critical, to proper machine operation. Such data may include, for example, engine speed, fuel/air mixture, temperature, and various other parameters. The data, after collected and processed, can be used to evaluate the performance of the machine and, more specifically, the engine. More recently, with the implementation of emission control requirements, electronic controllers are commonly used to facilitate more efficient operation of the engine by affecting control decisions based on the data it has collected and processed. These sophisticated electronic controllers consist of central processing units and assorted inputs and outputs dedicated to controlling various components within the engine system of a machine.
The desire to provide such precise control to various other systems, or subsystems, of a machine has led to the implementation of multiple electronic controllers. Although there are a number of benefits to utilizing more than one electronic controller, multiple electronic controllers may cause a significant power draw on the electrical system of the machine. Specifically, for example, when the engine is off and the battery is not being continuously charged, the quiescent power draw from each electronic controller may reduce battery life. In machines utilizing multiple electronic controllers, this quiescent power draw may become quite significant. For example, if the engine has not been started for a period of time, and, therefore, the battery recharged, the power draw may deplete the battery and an operator may be unable to start the machine.
U.S. Pat. No. 5,834,854 teaches a system for reducing electrical power to electronic modules after a “key-off” of a motor vehicle. Specifically, an electrical power input of each of a plurality of electronic modules is switchably coupled to a vehicle system voltage. During “key-on,” the switchable connection to the vehicle system voltage is closed, thereby providing “key-on” power for the modules from the system voltage. During “key-off,” the switchable connection is opened, thereby providing “key-off” power for the electronic modules from a switching power supply. The “key-off” power provided through the switching power supply may represent a reduced amount of power relative to the “key-on” power. It should be appreciated, however, that there remains a continuing need for improved strategies for reducing quiescent power draw in machines having electronic control systems.
The present disclosure is directed to one or more of the problems set forth above.